The singer, the late Hui Kahu, is her "nan", who died in 2012, aged 73.
The song was performed by the Patea Maori Club.
The original club included several of her family members including her nan, her "koko" (grandfather) Sid Kahu and her mother Terina Kahu.
The song was recorded in the Taranaki town of Patea in 1983, the same year Miss Kahu-Luke was born.
The University of Otago College of Education student has vivid memories of sitting on stairs watching her family perform the song on stage.
Her nan was chosen by "Uncle Dal" (song co-writer Dalvanius Prime) to sing the introduction because "Nan hit the right tone for his ear".
She never expected the song to "blow up" and become a hit with a broad appeal.
Last night, she and sons Eli (14) and Lucca Ellison (5) watched writer-director Tearepa Kahi’s Poi E: The Story Behind Our Song, which opened the Dunedin programme of the New Zealand International Film Festival at the Regent Theatre.
She got emotional when she collected her ticket at the box office yesterday.
"The hardest thing was hearing Poi E after Nan passed away because that’s her voice and by buying the ticket ... it hit me, I had to admit she wasn’t here."
The film would show her son what her nan was about and how she used the song to promote the Maori language.
"She travelled the world, promoting the Maori language singing Poi E."
Her nan was a teacher so she decided to "follow in her footsteps" and began studying in Dunedin this year.
Everyone should see the film.
"I think in some way Patea relates to everybody, they’ll look at their own hometown and they’ll see the people that they learned from, whether Maori, Pakeha or Chinese . . . there is a little bit of Patea in everybody."
